Articulated vacuum pad for industrial truck



Oct. 4, 1966 E. A. HORTON 3,

ARTICULATED VACUUM PAD FOR INDUSTRIAL TRUCK Filed Feb. 2'7, 1963 3 Sheets=-Sheet 1 INVENTOR. 4 E. '4. Haw-0N A T'FOPNEV E. A. HORTON ARTICULATED VACUUM PAD FOR INDUSTRIAL TRUCK Oct. 4,1966

5 Sheets-Sheet 2 Filed Feb. 27, 1963 Oct. 4, 1966 E. A. HORTON ARTICULATED VACUUM PAD FOR INDUSTRIAL TRUCK 5 Sheets-$heet 3 Filed Feb. 27. 1963 INVENTOR.

,4 rmp/v/sy 15 4. f/o ro/Y BYww A Ti

United States Patent 3,276,611 ARTICULATED VACUUM PAD FOR INDUSTRIAL TRUCK Earl A. Horton, Philadelphia, Pa., assignor, by mesne assignments, to Eaton Yale & Towne, Inc., a corporation of Ohio Filed Feb. 27, 1963, Ser. No. 261,257 Claims. (Cl. 214-650) This invention relates to industrial lift trucks, and more particularly to a novel load gripping vacuum attachment for a truck of the particular kind.

Those persons skilled in the art will appreciate that a vacuum pad, to be effective for holding a load, must first be brought into particular contact with the surface of the load. That generally creates a considerable problem when the vacuum pad is utilized on a lift truck, because it requires that the operator of the truck use extreme care in maneuvering the truck so as to place the pad in the correct position on the load surface. It is still more difficult to position the vacuum pad when the load presents a curved surface, as when the load is a roll of paper, and frequently the operator of the truck must realign the truck, causing much loss of time.

The prior art does contain many examples of vacuum pads that are intended to be self-aligning, but insofar as I am aware, no one until the present time has developed a construction that operates with full satisfaction when used on a lift truck. I have now conceived by my invention a novel articulated construction .that will enable a lift truck to position a vacuum pad automatically and with extremely good effect as the truck moves the pad toward the surface of a load. Moreover, my construction will operate exceedingly well when the vacuum pad is utilized for engaging the curved surface of a roll of paper.

In my invention, I support one or more load engaging vacuum pads through an articulating mounting that allows the pads to have floating movements on the load carriage of a lift truck. As a part of that mounting, I utilize springs that press the vacuum pads to a predetermined normal position relatively to the load carriage, but those springs are so arranged as to yield when the pads are brought against the surface of a load. The pads then will move automatically in any direction that is required in order to achieve the proper contact with the load. There are stop surfaces that will act to limit the articulating movements of the vacuum pads, so as to support a load held on the pads in a particular position relatively to the load carriage of the truck when the carriage lifts the load.

In my preferred construction, I utilize upper and lower pin and slot connections between each side of the load carriage of the truck and each side of the vacuum pads. The pin and slot connections are arranged to permit lateral swinging of the vacuum pads about the upper and lower pins at one or the other side to the limit permitted by the pin and slot connections at the opposite side. By the movement of all of the pins in their slots, the vacuum pads can have bodily movement to the extent of the slots. In addition, the vacuum pads can swing vertically about the upper pins or the lower pins to the limit of the slots at the opposite lower or upper pins.

In effect, the pin and slot connections of my invention will enable a vacuum pad to have universal swinging movements, while also allowing the pad to yield bodily in a fore-and-aft direction relatively to the truck.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be bet ter appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art.

In the drawings:

FIG. 1 shows a lift truck that utilizes my novel articulating vacuum pad attachment;

FIG. 2 shows a front view of my invention;

FIG. 3 shows a plan view of my invention;

FIG. 4 shows a vertical section showing parts of my invention on the line 4-4 in FIG. 2;

FIG. 5 illustrates the position of my attachment when supporting a load; and

FIG. 6 shows the position of my attachment when the truck is off-center while moving to engage the load.

Referring now more particularly to FIG. 1 of the drawings, I show my novel attachment 10 mounted on the load carriage 11 of a lift truck T. The load carriage 11 will move vertically on uprights 12 at the front end of the truck T, and there is tilt mechanism13 which can be actuated to tilt the uprights 12 and carriage 11 in a foreand-aft direction relatively to the truck, that being a usual arrangement in trucks of the particular class. -FIG. 1 further shows a load rotating device 14 that is arranged between my novel attachment 10 and the load carriage 11, enabling the truck to upend a load that is held on the attachment. However, it is merely important to know at this point that the truck T supports my attachment 10 for vertical lifting movement, and we may simply con sider that the attachment is mounted on the load carriage 11.

In the form of my invention that I prefer and that I show in the drawings, the attachment 10 includes a pair of vacuum pads 15 that are adapted to engage the curved surface of a roll of paper R which is shown in FIG. 3, and a support plate 16 through which the pads 15 are supported on a vertical base plate 17. As best shown in FIGS. 2 and 4, I mount a pair of plate-like brackets 18 in forwardly extending position on an upper portion of the vertical base plate 17. The brackets 18 also extend in a lateral direction, and are so spaced relatively to each other as to accept between them a lug 19 that is integrally mounted on the back of the support plate 16. For reasons that will appear, I arrange some clearance in a vertical direction between the juxtaposed surfaces of lug 19 and brackets 18.

Referring to FIGS. 2 and 3, I utilize the brackets 18 to support two pins 20, 21 in vertical positions at opposed lateral sides of the base plate 17. Further, as shown in FIGS. 3 and 4, I form the lug 19 with slots 22, 23, for the pins 20, 21, those slots extending in a fore-and-aft direction relatively to the truck.

Between lower portions of the base plate 17 and support plate 16, I utilize a pin and slot arrangement like that which I have just described. Thus, there are two lower pins 25, 26 that are supported through plate-like brackets 27 so as to be arranged in vertical positions at opposed lateral sides of the base plate 17, and that engage slots 28, 29 in a lug 30 on the support plate 16. It will be seen, therefore, that I mount the support plate 16 through upper and lower pin and slot connections between each lateral side of a load carriage and each lateral side of plate 16. Thus, in a usual position of the base plate 17, there will be -a set of the upper and lower connections at each side of the longitudinal center of the truck. In effect, the pin and slot connections comprise lost motion means that mount support plate 16 for universal swinging movement on the load carriage of a truck.

Near each of the upper and lower vertical pins 20, 21, 25, 26 is a coil spring 31 that acts between the base plate 17 and support plate 16 to press the support plate in a forward direction. As indicated in FIG. 4, opposed ends of each spring 31 are held on a spring guide 32 on support plate 16, and a bolt 33 that may be one of the bolts assembling the base plate 17 to the load rotating device 14. Due to the forward pressure of the coil springs 31, the rearward ends of all of the slots 22, 23, 28, 29 normally will be pressed to a limit position against their corresponding pins 20, 21, 25, 26. Thus, the spring pressure is adapted to hold the support plate 16 in a predetermined normal position relatively to the lift truck. However, each spring 31 by yielding will enable the support plate 16 to have certain movements, those movements being limited through en-gagament of the forward end of one or more slots 22, 2 3, 28, 29 with their corresponding pins.

In more detail, the support plate 16 can swing in one lateral direction through pivotal movement about the upper and lower pins 20, 25 at one side to the limit of the slots 23, 29 at the other side, that being the movement which is indicated in FIG. 6. The support plate 16 may have a similar swinging movement in the opposed lateral direction, but the pivoting then will be about the pins 21, 26. Funther, the support plate 16 can swing downwardly about the lower pins 25, 26 to the limit of the upper slots 22, 23, that being the movement illustrated in FIG. 5, and the support plate 16 can swing upwardly in a similar manner about the upper pins 20, 21. It will be seen also that the support plate 1 6 can yield bodily in a rearward direction through movement of all of the slots on their pins.

Let us now refer in more detail to the construction of the support plate 16 and the vacuum pads 15. In the construction that I prefer, the support plate 16 is somewhat I-shaped, as indicated in FIG. 2, each side of the plate having angular upper and lower portions 35 that extend laterally. Those portions 35 also are inclined in a forward direction, as may be seen in FIG. 3. Each of the angular side portions 35 is equipped with a sleeve 36, there being a vertical shaft 37 supported on the sleeves 36 at each side of the plate. Each vacuum pad 15 is constructed with a curved base 38, best seen in FIG. 3, that is pivotally supported through brackets 39 on a corresponding vertical shaft 37. A flexible member 40 extends across the front surface of each base part 38, opposed ends of said member being so clamped to the base 38 as to leave yielding portions 41 that normally are in spaced relation to the front of the base. A vacuum sealing member 42 is secured in position extending circumferentially on a front surface of each flexible member 40. Further, I utilize a leaf spring 43, FIG. 3, acting in such a way between the base part 38 of each vacuum pad 15 and the support plate 16 as to rotate the pad in an outward direction about its pivot shaft 37. A stop portion 44 on the end of support plate 16 will limit the outward rotation of each pad 15.

The leaf springs 43 will yield so that the vacuum pads 15 can rotate about the vertical shafts 37, enabling the vacuum pads 15 to align themselves through contact with the surface of the roll R. Further, side portions 42a, 42b of the vacuum sealing member 42 can move through yielding of the flexible member 40', so as to conform to the curved surfaces of rolls that may have different diameters. Moreover, despite the curvature of the roll surface, the laterally outward portion 42b of each vacuum sealing member 42, or in other words the portion which is farthest from the center line of the truck, will move into effective sealing contact with the roll surface without substantial sliding on that surface. That is because the springs 43 will so position the vacuum pads 15 that the laterally inward portion 42a of each sealing member 42 will engage the roll first. The pads then will rotate on shafts 37 to bring the laterally outward portions 42b of sealing members 42 in a perpendicular direction against the roll surface. Thereby, I eliminate a tendency of the outer portions of the sealing members to fold over due to the longitudinal movement of the truck.

In FIG. 3 I show a limit switch 45 which forms a part of an automatic control for the vacuum which is applied to the pads 15. That control may be constructed in the manner which is described in my earlier Patent No. 2,942,745, and I believe it will be unnecessary here to go into detail as to the vacuum control. As shown in FIG. 3, switch 45 actually is mounted in position in a box 47 that extends from the back surface of one vacuum pad 15, there actually being a box 47 on each pad 15. Those boxes 47 are arranged to move against stops 46 which will limit the lateral articulating movements of support plate 16. The stop members 46 may very well be mounted on angular reservoirs 48 that I utilize for the vacuum system of the truck, and that are so arranged on the base plate 17 as to lie in the angular spaces between base plate 17 and the opposed sides of plate 16.

I shall now review the operation of my novel articulated vacuum pad construction. When the operator of the truck wishes to lift a roll of paper, he first will try to maneuver the truck so as to approach the roll in a line that is centered relatively to the roll, that being the usual procedure when moving a lift truck toward a load. While the operator does that, the coil springs 31, FIG. 3, will hold the vacuum pads 15 in normal centered position relatively to the'truck.

If the operator actually succeeds in centering the truck, the vacuum pads 15 Will be moved toward positions shown in FIG. 3, which are symmetrically arranged at either side of the center line of roll R. In those positions, the laterally inward portion 42a of each sealing member has engaged the roll surface. That will cause the vacuurn pads 15 to rotate inwardly through yielding of the leaf springs 43 as the truck continues to move toward the roll R. The outward portions 42b of the sealing members then will move substantially in a perpendicular direction against the roll surface, as indicated by the arrows in FIG. 3. Therefore, in my invention, the linear movement of the truck will not tend to slide the outward portions 42b of the sealing members to any great extent on the curved sides of the roll R, and will not cause the members to fold into an ineffective sealing position.

The vacuum sealing members 42 normally have a curvature which is sharper than that of the roll R, as shown in FIG. 3, so that those members 42 may effectively coact with a smaller roll. However, the sealing members 42 easily may assume a flatter curvature through yielding of the flexible portions 41 on each vacuum pad 15, so as to make eflicient contact with the surface of a roll such as the roll R.

When the pads 15 have moved into full sealing contact with roll R, vacuum will be applied to the pads and the operator will stop the forward motion of the truck. In my invention, it will be realized that the operator actually need not stop the truck in an exact position since the coil springs 31 may yield, allowing a bodily rearwarcli movement of the vacuum pads 15 relatively to the truc After vacuum is applied to the pads 15, the operator may actuate the load carriage of the truck to lift the roll R. When the vacuum pads 15 support the roll, as in FIG. 5, the weight of the roll will cause the lower slots 28, 29 to move rearwardly on their pins 25, 26, while the support plate 16 pivots about the upper pins 20, 21. The roll R will then be supported in a slightly tilted position,

which the operator may compensate through tilting of the truck uprights 12.

Now let us refer to FIG. 6 to see what happens when the operator has not succeeded in centering the truck relatively to the roll R. Thus, the truck has caused the left-hand vacuum pad 15, that being the upper pad as viewed in FIG. 6, to move first against the roll R. Nevertheless, the opposed right-hand pad 15 has come into full contact with the roll surface through yielding of certain coil springs 31. More particularly, the support plate 16 has swung about the right-hand pins 20, 25, while yielding of springs 31 has permitted the left-hand slots 23, 29 to move on their pins. Upon lifting of the roll, the support plate 16 will return to a medial position due to the centering effect of the coacting pins and slots.

I have described my invention while referring to a roll R that is positioned with its axis vertical, but it is to be understood that the operation in effect will be the same when the roll axis is horizontal. Thus, should the vacuum pads 15 be rotated 90 for handling a horizontal roll, those pads again will articulate, with the support plate 16 swinging about the pins that then are at either side, or at the top or bottom.

It will now be seen that my novel vacuum pad construction will operate very effectively to grip a load even though the truck does not move into a precise position relatively to the load. Through the universal movement of my vacuum pads, the truck may very efiiciently engage a load when somewhat to the right or left of the load, or even when the load is in a tilted position. When moved against the load, the vacuum pads can yield bodily so that the operator need not take extreme care to stop the movement of the truck at an exact point. Moreover, the vacuum sealing members on the vacuum pads will operate very well when handling rolls of different diameters.

Through the novel concept of my invention, I am able to equip an industrial lift truck with load gripping vacuum means that will operate exceedingly well as compared to those of the prior art, and that will contribute much better efiiciency in the operation of the truck. I

believe, therefore, that the very considerable value of my novel load gripping construction will be fully understood, and that the merits of my invention will be fully appreciated by those skilled in the art.

I claim:

1. In an industrial truck of the class described, a load carriage mounted for vertical lifting movement, a pair of load gripping vacuum pads mounted in position on said load carriage for engaging opposed side portions of a roll of paper when the truck moves toward the roll, each vacuum pad of said pair of pads having a vacuum sealing member extending circumferentially on the front surface of the pad, means mounting each pad to rotate on a vertical axis, and a spring acting against each vacuum pad for pressing the pad to an outwardly rotated position in which a laterally inward portion of its sealing member is closer to the surface of the roll than is a laterally outward portion of said member as the truck moves toward the roll, so that said inward portion will engage the roll first, and said laterally outward portion will move substantially in a perpendicular direction against the roll surface through inward rotation of the pad as the truck continues to move towards the roll.

2. In an industrial truck of the class described, a load carriage mounted for vertical lifting movement, a vertical support plate, means mounting the support plate on the load carriage, including upper and lower pin and slot connections between said load carriage and said support plate at one side of the longitudinal center of the truck, upper and lower pin and slot connections between said load carriage and support plate at the other side of the longitudinal center of the truck, the slots of said connections extending in a fore-and-aft direction, spring means acting between said carriage and support plate to press said plate in a forward direction, the spring pressure pressing the pins toward one end of the slots for holding the support plate in a predetermined position relatively to the carriage, a pair of load gripping vacuum pads mounted in position on said support plate for engaging opposed side portions of a roll of paper when said plate is in its predetermined position and the truck moves forwardly toward the roll, each vacuum pad having a circumferentially extending vacuum sealing member, means mounting each pad to rotate in a vertical axis, a spring pressing each vacuum pad to an outwardly rotated position which will cause a laterally outward portion of its sealing member to move substantially in a perpendicular direction against the roll surface through inward rotation of the pad when engaging the roll, the spring means that press the support plate yielding to enable each pin to move in a rearward direction in its slot, whereby to allow the pressure of a load against the vacuum pads to swing said pads about the upper and lower pins at one or the other side to the limit permitted by the upper and lower pin and slot connections at the opposite side, and also to move said vacuum pads bodily in a rearward direction relatively to said carriage to the extent of all of said slots, and to swing the pads about the upper pins or the lower pins to the limit of the slots at the opposite lower or upper connections, while said pads rotate to adjust their positions relatively to each other on their mountings.

3. In an industrial truck of the class described, a load carriage mounted for vertical lifting movement, a vertical support plate having load engaging means for supporting a load in position in front of said carriage and forming the sole support for the load, means mounting the vertical support plate for substantially universal movement on the load carriage, comprising upper and lower pin and slot connections between each lateral side of said load carri-age and each lateral side of said support plate permitting pivotal swinging of said support plate and load engaging means in a lateral direction about the upper and lower pins at one or the other side to the limit permitted by the pin and slot connections at the opposite side, said pin and slot connections allowing bodily movement of said support plate and load engaging means relatively to said carriage to the extent of all of the slots together with swinging movement in a vertical direction about the upper pins or the lower pins to the limit of the slots at the opposite lower or upper pins, means biasing said support plate in a forward direction, and end portions of said slots engaged by the pins whereby to accept moment due to the weight of a load supported by said load engaging means.

4. In an industrial truck of the class described, a load carriage mounted for vertical lifting movement, a vertical support plate having load engaging means for supporting a load in position in front of said carriage and forming the sole support for the load, means mounting the vertical support plate for substantially universal movement on the load carriage, comprising upper and lower pin and slot connections between said load carriage and said support plate at one side of the longitudinal center of the truck, upper and lower pin and slot connections between said load carriage and support plate at the other side of the longitudinal center of the truck, the slots of said connections extending in a fore-and-aft direction relatively to the truck, spring means acting between said carriage and support plate to press said plate in a forward direction, the spring pressure pressing the pins toward one end of the slots for holding the support plate in a predetermined position relatively to the carriage, said spring means yielding to enable each pin to move in its slot while a portion of the plate moves rearwardly, whereby to allow the pressure of a load against the load engaging means to swing said support plate and load engaging means in a lateral direction about the upper and lower pins at one or the other side to the limit permitted by the upper and lower pin and slot connections at the opposite side, and also to move bodily said support plate and load engaging means to the extent of all of said slots, and to swing the support plate and load engaging means in a vertical direction about the upper pins or the lower pins to the limit of the slots at the opposite lower or upper connections, and certain ends of said slots engaged by the pins whereby to accept moment due to the weight of a load supported by said load engaging means.

5. In an industrial truck of the class described, a load carriage mounted for vertical lifting movement, a vertical support plate having load gripping vacuum means for supporting a load in position in front of said carriage and forming the sole support for the load, means mounting the vertical support plate for substantially universal movement on the load carriage, comprising a vertical pin and slot connection between said load carriage and said support plate at one side of the longitudinal center of the truck, and a like pin and slot connection at the other side of the longitudinal center of the truck, said connections being so arranged that the slots extend in a fore-and-aft direction relatively to the truck, spring means pressing the support plate in a forward direction for holding the pins against one end of the slots whereby to hold the support plate in a predetermined position, said spring means yielding due to the pressure of said load gripping means relatively to a load whereby to efiect pivotal swinging of said support plate and load engaging means in a lateral direction about one pin or the other to the limit of said slots, and bodily fore-and-aft movement of said support plate and load gripping means to the extent of both slots, and certain ends of said slots engaged by the pins whereby to accept moment due to the weight of a load supported by said load gripping means.

References Cited by the Examiner GERALD M. FORLENZA, Primary Examiner.

MORRIS TEMIN, H'UGO O. SCHULZ,

R. JOHNSON, Examiners. 

1. IN AN INDUSTRIAL TRUCK OF THE CLASS DESCRIBED, A LOAD CARRIAGE MOUNTED FOR VERTICAL LIFTING MOVEMENT, A PAIR OF LOAD GRIPPING VACUUM PADS MOUNTED IN POSITION ON SAID LOAD CARRIAGE FOR ENGAGING OPPOSED SIDE PORTION OF A ROLL OF PAPER WHEN THE TRUCK MOVES TOWARD THE ROLL, EACH VACUUM PAD OF SAID PAIR OF PADS HAVING A VACUUM SEALING MEMBER EXTENDING CIRCUMFERENTIALLY ON THE FRONT SURFACE OF THE PAD, MEANS MOUNTING EACH PAD TO ROTATE ON A VERTICAL AXIS, AND A SPRING ACTING AGAINST EACH VACUUM PAD FOR PRESSING THE PAD TO AN OUTWARDLY ROTATED POSITION IN WHICH A LATERALLY INWARD PORTION OF ITS SEALING MEMBER IS CLOSER TO THE SURFACE OF THE ROLL THAN IS A LATERALLY OUTWARD PORTION OF SAID MEMBER AS THE TRUCK MOVES TOWARD THE ROLL, SO THAT SAID INWARD PORTION WILL ENGAGE THE ROLL FIRST, AND SAID LATERALLY OUTWARD PORTION WILL MOVE SUBSTANTIALLY IN A PERPENDICULAR DIRECTION AGAINST THE ROLL SURFACE THROUGH INWARD ROTATION OF THE PAD AS THE TRUCK CONTINUES TO MOVE TOWARDS THE ROLL. 